This disclosure relates to a high voltage lamp transformer assembly, winding arrangement and method of assembly. Specifically, the disclosed high voltage lamp transformer assembly can be mounted within an automotive headlamp module, for example a D1 or D5 automotive headlamp module. The disclosed transformer assembly and winding arrangement is particularly well suited as a high voltage lamp igniter transformer for lamp applications requiring a relatively large amount of current during ignition while maintaining a relatively small transformer size.
Conventionally, high voltage igniter circuits are used to start HID lamps. One example of a HID lamp requiring a high voltage ignition is an automotive lamp commonly referred to as a headlamp. To produce the high voltage ignition signal, an igniter circuit is operatively connected to the HID lamp. The igniter circuit typically includes a lead frame and a high voltage transformer arrangement. The high voltage transformer is necessary to produce the required lamp ignition high voltage signal, which may be as high as 30 kV. For purposes of this disclosure, high voltage refers to voltages in the approximate range of 1 kV-30 kV and low voltage refers to voltages less than 1 kV.
U.S. Patent Application Publication 2004/0066150 discloses a gas discharge lamp base comprising a conventional ignition circuit. The housing includes a compartment within the housing to contain a high voltage ignition bar core transformer which is mounted to a lead frame (FIG. 3). The igniter module is connected to a DC source via a connector which may be molded directly to the housing.
U.S. Pat. No. 6,731,076 discloses another conventional gas discharge lamp base and associated components. The gas discharge lamp base comprises a carrier part (16) which carries electrical components and a toroidal core transformer (23) to ignite a gas discharge lamp (2). The toroidal shape of the transformer provides clearance for a housing top part (10) including an attached lamp mounting base to pass through the center of the toroid transformer.
Other examples of conventional shaped transformer cores include a core comprising a magnetic material with an open end, producing a “c” shaped or horseshoe shaped core. The open space at the longitudinal ends of the core can be coupled with a gap material to control the saturation of the transformer core, for example, air and/or epoxy.
This disclosure provides a lamp transformer assembly, winding arrangement, and method of assembly for use in a lamp module, for example a high voltage lamp ignition module. As compared to conventional lamp igniter transformers, this disclosure and embodiments herein provide a transformer core construction which can increase the saturation threshold of a transformer core and provide an increase in current delivered to a lamp from the transformer assembly.